Device for laying out regular polygons



(No Model.)

J. J. FOSS. DEVICE FOR LAYING OUT REGULAR POLYGONS.

A 7'TOHNEY Patented 1390.7,1897.

WITNESSES UNTTEn STATES PATENT OEEIcE.

JOHN J. FOSS, OF CLEVELAND, OHIO.

DEViCE FOR LAYING OUT REGULAR POLYGONS.

SPECIFICATION formingpart of Letters Patent No. 595,055, dated December 7, 1897.

Application filed M r h 19, 1897. Serial No. 628,259. (No model.)

To all whom it may concern.-

Be itknown that I, JOHN J. Foss, a citizen of the United States, and a resident of Cleveland, county of Ouyahoga, and State of Ohio, have invented a new and useful Improvement in Devices for Laying Out Regular Polygons, of which the following is a specification, the prin ciple of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure I represents a top elevation of my device, showing also the end of a bar or shaft. Fig. II represents a similar view looking at the bottom. Fig. III represents a vertical transverse crosssectional view. Fig. IV represents a top elevation showing in addition an attachment to the device; and Fig. V represents a view of a portion of my device, illustrating a modified use of same.

The tool consists of the two bars A and B, formed with the bifurcations a a and b b at each end of each bar, the bifurcations a forming one angle,bifurcations a forming another, I) a third, and b a fourth. The said angles are each equal to one of the interior angles of respective regular polygons which it is desired to lay out. The angles formed by a, a, Z), and Z) in the drawings are those of an equilateral triangle, a hexagon, an octagon, and a square, these polygons being of most common use. The said bifurcations are so formed that a produced line bisecting the angle at" one end of each bar will bisect the angle at the opposite end of the same bar. Each bar is formed with central longitudinal slots a and b of equal width. Two short bolts 0, provided with thumb-nuts O, are formed with a rectangular portion 0, which snugly fits in and slides within the two slots a and b when the bars are laid one upon the other. It is thus seen that the two bars can be made to slide one upon the other, the bisectors of their respective angles always remaining in the same plane passing longitudinally through the middle of the bars. Their relative positions may be fixed by screwing down the thumb-nuts and clamping the two parts.

The heads 0 of the bolts 0 are made square, the sides of said square being made parallel with the sides of the slots a and 11 These square heads fit exactly a slot (1 of an attachment D, which is formed of a flat metal sheet and has an extended portion (1, whose inner longitudinal edge d coincides with the produced middle line of the slot cl. This edge, when the attachment is placed upon the boltheads, gives the bisecting line of the angle to which it is applied.

It is desired to lay out a regular hexagon on the end of the shaft E, said hexagon having a diameter of one inch. The end of the shaft is inserted between the sides of the angle formed by the bifurcations b, which in this instance are opposite the bifurcations a, which form an angle of one hundred and twenty degrees, the interior angle of a hexagon. The shaft is thus centered by resting against both bifurcations, as is readily understood. The bar A is now slid up until the vertex of the angle of one hundred and twenty degrees is one inch from the center of the circle forming the end of the shaft. This center may have been previously determined by the use of the attachment D, two intersecting bisectors having been drawn upon the shaft, their intersection being the center of the circle. The position of the vertex having been determined, the two bars are firmly clamped together and a line is drawn upon the shaft, using the inside edge of one of the bifurcations a as a straight edge. The shaft is then rotated on its axis until the line just drawn coincides with the edge of the other bifurcation and a second line is drawn. The operation is repeated until all six sides have been drawn to complete the hexagon. Each of the other anglesmay be used in a similar manner to form their respective polygons.

In Fig. V, I have shown how a polygon may be drawn upon a flat surface, as a sheet of paper upon a table, by the use of one bar. It is desired to inscribe a hexagon in the circle F. An extended line f is drawn through the center of the circle. The bar A is detached and laid upon the sheet with the vertex of the one'hundred-andtwenty-degrec angle coinciding with the intersection of the line ff with the circumference of the circle. The vertex of the angle at the opposite end is made to fall upon the extension of said line. As before, a line'is drawn using one bifurcation as a straight edge, the bar revolved until the edge of the other bifurcation coincides with the line just drawn, and a second line drawn. The operation is repeated until the hexagon is completed.

Other modes of applying the principle of my invention maybe employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means covered by anyone of the following claims be employed.

I therefore particularly point out and distinctly claim as my invention- 1. In a device for laying out regular polygons, the combination with a bar provided with two straight edges forming an interior angle of a regular polygon, of a second bar provided with two similar straight edges forming an interior angle of a regular polygon having a number of sides varying from that of the first-named polygon, said two bars being longitudinally adjustable upon each other, the vertices of said angles always lying in the same plane perpendicular to the plane of one of said angles, substantially as set forth.

2. In a device for laying out regular polygons, the combination of a bar provided with two straight edges forming an interior angle of a regular polygon, of a second bar provided with similar straight edges forming an interior angle of the second polygon having a number of sides varying from that of the firstnamed polygon, each of said bars formed with a central longitudinal slot and longitudinally adjustable upon each other, and a bolt adapted to slide within said slot and provided with means for clamping said two bars together, the vertices of said angles always lying in the same plane perpendicular to the plane of one of said angles, substantially as set forth.

Signed by me this 16th day of March, 1897.

J NO. J. FOSS. Attest:

WILLIA NoBBE, A. E. MERKEL. 

